The rockefeller university

Cow's milk protein allergy in exclusively breastfed infants, the main cause of food intolerance during the first 6 months of life, is triggered by the mother's diet. beta-Lactoglobulin (BLG) present in cow's milk is one of the most potent allergens for newborns. Since no prophylactic treatment is available, finding ligands capable of binding BLG and reducing its allergenicity is currently the focus of research. In this work, an innovative methodology encompassing microfluidics based on fully automated chip-nanoelectrospray ionization (nanoESI), coupled with high-resolution mass spectrometry (MS) on a quadrupole time-of-flight (QTOF MS) instrument was developed. This platform was employed for the assessment of the noncovalent interactions between maltohexaose (Glc(6)) and beta-lactoglobulin extracted from human milk upon deliberate intake of cow's milk. The experiments were carried out in (+) ESI mode, using ammonium acetate (pH 6.0) as the buffer and also in pure water. In both cases, the MS analysis revealed the formation of BLG-Glc(6) complex, which was characterized by top-down fragmentation in tandem MS (MS/MS) using collision-induced dissociation (CID). Our findings have a significant biomedical impact, indicating that Glc(6) binds BLG under conditions mimicking the in vivo environment and therefore might represent a ligand, able to reduce its allergenicity.

Background: Atopic dermatitis (AD) shows very high prevalence in Asia, with a large unmet need for effective therapeutics. Direct comparisons between European American (EA) and Asian patients with AD are unavailable, but earlier blood studies detected increased IL-17 1 -producing cell counts in Asian patients with AD. Objective: We sought to characterize the Asian AD skin phenotype and compare it with the EA AD skin phenotype. Methods: We performed genomic profiling (real-time PCR) and immunohistochemistry on lesional and nonlesional biopsy specimens from 52 patients with AD (25 EAs and 27 Asians), 10 patients with psoriasis (all EAs), and 27 healthy subjects (12 EAs and 15 Asians). Results: Although disease severity/SCORAD scores were similar between the AD groups (58.0 vs 56.7, P 5.77), greater acanthosis, higher Ki67 counts, and frequent parakeratosis were characteristics of lesional epidermis from Asian patients with AD (P <.05). Most (24/27) Asian patients had high IgE levels. A principal component analysis using real-time PCR data clustered the Asian AD phenotype between the EA AD and psoriasis phenotypes. T(H)2 skewing characterized both Asian and EA patients with AD but not patients with psoriasis. Significantly higher T(H)17 and T(H)22 (IL17A, IL19, and S100A12 in lesional and IL-22 in nonlesional skin; P <. 05) and lower T(H)1/interferon (CXCL9, CXCL10, MX1, and IFNG in nonlesional skin; P <.05) gene induction typified AD skin in Asian patients. Conclusion: The Asian AD phenotype presents (even in the presence of increased IgE levels) a blended phenotype between that of EA patients with AD and those with psoriasis, including increased hyperplasia, parakeratosis, higher T(H)17 activation, and a strong T(H)2 component. The relative pathogenic contributions of the T(H)17 and T(H)2 axes in creating the Asian AD phenotype need to be tested in future clinical trials with appropriate targeted therapeutics.

People learn modality-independent, conceptual representations from modality-specific sensory signals. Here, we hypothesize that any system that accomplishes this feat will include three components: a representational language for characterizing modality-independent representations, a set of sensory-specific forward models for mapping from modality-independent representations to sensory signals, and an inference algorithm for inverting forward models-that is, an algorithm for using sensory signals to infer modality-independent representations. To evaluate this hypothesis, we instantiate it in the form of a computational model that learns object shape representations from visual and/or haptic signals. The model uses a probabilistic grammar to characterize modality-independent representations of object shape, uses a computer graphics toolkit and a human hand simulator to map from object representations to visual and haptic features, respectively, and uses a Bayesian inference algorithm to infer modality-independent object representations from visual and/or haptic signals. Simulation results show that the model infers identical object representations when an object is viewed, grasped, or both. That is, the model's percepts are modality invariant. We also report the results of an experiment in which different subjects rated the similarity of pairs of objects in different sensory conditions, and show that the model provides a very accurate account of subjects' ratings. Conceptually, this research significantly contributes to our understanding of modality invariance, an important type of perceptual constancy, by demonstrating how modality-independent representations can be acquired and used. Methodologically, it provides an important contribution to cognitive modeling, particularly an emerging probabilistic language-of-thought approach, by showing how symbolic and statistical approaches can be combined in order to understand aspects of human perception.

The hepatitis C virus (HCV) p7 protein is required for infectious virus production via its role in assembly and ion channel activity. Although NMR structures of p7 have been reported, the location of secondary structural elements and orientation of the p7 transmembrane domains differ among models. Furthermore, the p7 structure-function relationship remains unclear. Here, extensive mutagenesis, coupled with infectious virus production phenotyping and molecular modeling, demonstrates that the N-terminal helical region plays a previously underappreciated yet critical functional role, especially with respect to E2/p7 cleavage efficiency. Interrogation of specific N-terminal helix residues identified as having p7-specific defects and predicted to point toward the channel pore, in a context of independent E2/p7 cleavage, further supports p7 as a structurally plastic, minimalist ion channel. Together, our findings indicate that the p7 N-terminal helical region is critical for E2/p7 processing, protein-protein interactions, ion channel activity, and infectious HCV production.

Huntington's disease (HD) is a neurodegenerative disorder characterized by massive loss of medium spiny neurons in the striatum. However, the mechanisms by which mutant huntingtin leads to this selective neuronal death remain incompletely understood. Brain-derived neurotrophic factor (BDNF) has been shown to be neuroprotective on HD striatal neurons both in vitro and in vivo. ProBDNF, the precursor of mature BDNF (mBDNF), also can be secreted but promotes apoptosis of neurons expressing p75(NTR) and sortilin receptors. Although a reduction of total striatal BDNF protein has been reported in HD patients and mouse models, it remains unclear whether conversion of proBDNF to mBDNF is altered in HD, and whether the proBDNF receptors, p75(NTR) and sortilin are dysregulated, leading to impaired striatal neuron survival. To test these hypotheses, we generated bdnf-HA knock-in (MI) mice on the zQ175 HD background to accurately quantitate the levels of both proBDNF and mBDNF in the HD striatum. In aged zQ175 HD mice, we observed a significant loss of mBDNF and decreased TrkB activation, but no increase of proBDNF or p75(NTR) levels either in the sensorimotor cortex or the striatum cortilin receptor are both increased in immature striatal oligodenHD striatum. Taken together, the present study through the TrkB receptor, rather than an induction factor to the vulnerability of striatal neurons in the zQ175 HD mouse model. (C) 2015 Elsevier Inc All rights reserved.

Prokaryotic organisms are threatened by a large array of viruses and have developed numerous defence strategies. Among these, only clustered, regularly interspaced short palindromic repeat (CRISPR)-Cas systems provide adaptive immunity against foreign elements. Upon viral injection, a small sequence of the viral genome, known as a spacer, is integrated into the CRISPR locus to immunize the host cell. Spacers are transcribed into small RNA guides that direct the cleavage of the viral DNA by Cas nucleases. Immunization through spacer acquisition enables a unique form of evolution whereby a population not only rapidly acquires resistance to its predators but also passes this resistance mechanism vertically to its progeny.

Several independent groups question the reliability of an antibody-based method that is used to isolate oogonial stem cells from the ovaries of adult humans, nonhuman primates and mice.

Background & Aims: Hepatitis B virus (HBV) infects and replicates in quiescent hepatocytes, which are deficient in dNTPs, the critical precursors of HBV replication. Most tumor viruses promote dNTP production in host cells by inducing cell proliferation. Although HBV is known as a major cause of hepatocellular carcinoma, it does not lead to cellular proliferation. Instead, HBV acquires dNTPs by activating the expression of the R2 subunit of the Ribonucleotide Reductase (RNR) holoenzyme, the cell cycle gene that is rate-limiting for generation of dNTPs, without inducing the cell cycle. We wished to elucidate the molecular basis of HBV-dependent R2 expression in quiescent cells. Methods: Quiescent HepG2 cells were transduced with an HBV-containing lentiviral vector, and primary human hepatocytes were infected with HBV. DNA damage response and RNR-R2 gene expression were monitored under this condition. Results: We report here that HBV-induced R2 expression is mediated by the E2F1 transcription factor, and that HBV induces E2F1 accumulation, modification and binding to the R2 promoter. We found that Chk1, a known E2F1 kinase that functions in response to DNA damage, was activated by HBV. In cells where Chk1 was pharmacologically inhibited, or depleted by shRNA-mediated knockdown, HBV-mediated R2 expression was severely attenuated. Furthermore, we found that HBV attenuates DNA repair, thus reducing cellular dNTP consumption. Conclusions: Our findings demonstrate that HBV exploits the Chk1-E2F1 axis of the DNA damage response pathway to induce R2 expression in a cell cycle-independent manner. This suggests that inhibition of this pathway may have a therapeutic value for HBV carriers. (C) 2015 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.

DNA double-strand break repair involves phosphorylation of histone variant H2AX ('gamma H2AX'), which accumulates in foci at sites of DNA damage. In current models, the recruitment of multiple DNA repair proteins to gamma H2AX foci depends mainly on recognition of this 'mark' by a single protein, MDC1. However, DNA repair proteins accumulate at gH2AX sites without MDC1, suggesting that other 'readers' of this mark exist. Here, we use a quantitative chemical proteomics approach to profile direct, phospho-selective gamma H2AX binders in native proteomes. We identify gamma H2AX binders, including the DNA repair mediator 53BP1, which we show recognizes gamma H2AX through its BRCT domains. Furthermore, we investigate the targeting of wild-type 53BP1, or a mutant form deficient in gamma H2AX binding, to chromosomal breaks resulting from endogenous and exogenous DNA damage. Our results show how direct recognition of gamma H2AX modulates protein localization at DNA damage sites, and suggest how specific chromatin mark-reader interactions contribute to essential mechanisms ensuring genome stability.

A search for a heavy Higgs boson in the H -> WW and H -> ZZ decay channels is reported. The search is based upon proton-proton collision data samples corresponding to an integrated luminosity of up to 5.1 fb(-1) at root s = 7 TeV and up to 19.7 fb(-1) at root s = 8 TeV, recorded by the CMS experiment at the CERN LHC. Several final states of the H -> WW and H -> ZZ decays are analyzed. The combined upper limit at the 95% confidence level on the product of the cross section and branching fraction exclude a Higgs boson with standard model-like couplings and decays in the range 145 < m(H) < 1000 GeV. We also interpret the results in the context of an electroweak singlet extension of the standard model.